Answers
Topic :-
- Linear Equation in Two Variable
Given :-
- 49x - 57y = 172 . . . .equation (1)
- 57x - 49y = 252 . . . . equation (2)
To Find :-
- Value of 'x' and 'y'.
Solution :-
Adding equation (1) and (2) :-
(49x - 57y) + (57x - 49y) = 172 + 252
Opening brackets,
49x - 57y + 57x - 49y = 172 + 252
Grouping similar terms,
(49x + 57x) + (-57y - 49y) = 172 + 252
Solving further,
106x + (-106y) = 424
106x - 106y = 424
106(x - y) = 424
x - y = 424/106
x - y = 4 . . . . equation (3)
Subtracting equation (1) from (2) :-
(57x - 49y) - (49x - 57y) = 252 - 172
Opening brackets,
57x - 49y - 49x + 57y = 252 - 172
Grouping similar terms,
(57x - 49x) + (57y - 49y) = 252 - 172
Solving further,
8x + 8y = 80
8(x + y) = 80
(x + y) = 80/8
x + y = 10 . . . . . equation (4)
Adding equation (3) and (4) :-
(x - y) + (x + y) = 4 + 10
Opening brackets,
x - y + x + y = 4 + 10
Grouping similar terms,
(x + x) + (y - y) = 4 + 10
Solving further,
2x + 0 = 14
x = 14/2
x = 7
Subtracting equation (3) from (4) :-
(x + y) - (x - y) = 10 - 4
Opening brackets,
x + y - x + y = 10 - 4
Grouping similar terms,
(x - x) + (y + y) = 10 - 4
Solving further,
0 + 2y = 6
y = 6/2
y = 3
Answer :-
- x = 7
- y = 3